Combustion apparatus



Em, W, W35,

L. w. CORBETT 2,@23,577

COMBUSTION APPARATUS Filed Jan. 26, 1932 2 Sheets-Sheet l INVENTOR w, WQMGAMQLM ATTORNEY Des. M, M35.

L. W. CORBETT COMBUSTION APPARATUS Filed Jan. 26, 1952 2 Sheets-Sheet 2INVENTOR ATTOR EY Patented Dec. 10, 1935 UNITED STATES PATENT OFFICECOMBUSTION APPARATUS Doble, Quincy, Mass.

Application January 26, 1932, Serial No. 588,881

2 Claims.

This invention relates to combustion apparatus for burning solid fuel,and more particularly to heating apparatus for domestic purposes, suchas to apparatus for heating dwelling houses and 5 garages, moderatesized buildings, and also for heating water for domestic purposes.

In general, the invention has for an object to provide a novel andimproved construction of heating apparatus of the character specified 10which is adapted to efficiently burn the various commercial grades ofcoal and coke in such manner as to avoid interruption in its operationby reason of the formation of clinker in the fuel bed.

With this object in view and such other objects as may hereinafterappear, the invention consists in the combustion apparatus and in thestruc tures, arrangements and combinations of parts hereinafterdescribed and particularly defined in the claims at the end of thisspecification.

In the drawings illustrating the preferred embodiment of the invention,Fig. l is a vertical sectional view of the preferred form of combustionapparatus; Fig. 2 is a side elevation of the lower portion of the heaterillustrating the mechanism 25 for rotating the grate; Figs. 3 to 6 arediagrammatic details in plan illustrating different positions assumed bycontiguous portions of the upper and. next lower sections of the grate;and

7 Figs. 7 and 8 are views in plan and vertical section respectively ofthe improved grate.

In general, the present invention contemplates a combustion apparatusfor burning solid fuel,

such as any of the commercial grades of coal, in

which provision is made for reducing to a minimum the formation ofclinker in the fuel bed.

The combustion apparatus is provided with a combustion chamber and witha grate for operatively supporting the fuel bed. 'The grate may andpreferably will be inclined and the fuel deposited upon the upperportion thereof to maintain a continuous fuel bed upon the grate ascombustion proceeds. Provision is made for agitating the fuel bed toreduce the formation of 45 clinker, and for this purpose the grate ispreferably provided with a section movable with relation to the mainbody of the grate in a direction such as to cause displacement of thefuel bed and to thereby effect agitation thereof. In the pre- 50 ferredform of the invention the grate is preferably of conical shape and theupper portion of the grate is made separate from the body of the grate.Provision is made for rotating the entire grate and, at the same time,for effecting oscilla- 55 tion of the upper section of the grate in ancccentric path to agitate the upper portion of the fuel bed.

Referring now to the drawings, I have for purposes of illustration shownthe invention as embodied. in combustion apparatus suitable for heatingdwelling houses and other moderate sized buildings, and for generalwater heating purposes, in which it represents a combustion chamber, 12a conical grate, it a supply hopper for retaining a supply of the solidfuel such as coal and from which the coal is discharged through a coaldischarge tube it down onto the conical grate. The end of the dischargetube terminates a short distance above the conical grate, and during theoperation of the apparatus 15 a constant bed of fuel is maintained inthe position indicated by the dotted line 25 in Fig. 1. It is preferredto construct the conical grate of a plurality of sections 26 whichinterlock to rotate as a unit, and the lower section 30 is preferablycast to provide a skirt 32, the upper surface of which is preferablysubstantially horizontal and of a sufficient width '30 that the skirtprojects outwardly a substantial distance beyond the inner wall of thelower portion of the combustion chamber. The lower portion of the innerwall is provided with ribs 35 for cooperation with the rotary grate ingrinding ash and such clinker as may be formed. The upper surface of theskirt 32- is spaced from the lower portion of the inner wall of thecombustion chamber to form a throat or constricted passage indicated at38.

The conical grate I2 is, as herein shown, made up of a plurality ofsections, and each section is provided with depending lugs 4? whichcooperate 35 with recesses in the next succeeding section to lock thesections together and to space one section a short distance from thenext lower section so as to provide a series of downwardly and outwardlyextending air channels t9 through which the primary air may be caused topass through the fuel bed supported upon the grate. The lower section ofthe grate is bolted or otherwise secured to a ring 43 having a ring gear44 cooperating with a driving pinion :35 secured upon 45 the end of adrive shaft it: rotated through suitable mechanism, as will bedescribed. The grate is supported on a series of ballbearings 53 withina raceway formed by cooperative surfaces 5'5, 58 of portions of thelower section of the grate and 59 ring 43 respectively, and an angularrecess in a supporting ring 59 mounted upon the frame, as shown. Theskirt 32.pro-jecting from thelower section of the grate is provided witha downwardly turned lip 60 extended over the supporting ring 59illustrated in detail in Fig. 3 to thereby assist in protecting thebearings against the entrance of ash and dirt.

The conical grate I2 is hollow, and as herein shown, cooperates with thebottom wall 64 of the burner pot to form a closed chamber 66 to whichair is admitted under pressure through an air inlet pipe 65 from anyconvenient source of supply, as for example a blower or fan, not shown.During the operation of the apparatus the air under pressure from withinthe closed air chamber 66 passes through the narrow air passages 49between successive sections of the grate to supply air for thecombustion of the fuel. The construction of air pressure chamber 66formed within the grate and burner pot serves to assist in preventingthe entrance of ash or dirt into the bearings 50 by reason of thepressure through the bearings and outwardly under "the projecting skirt.

During the operation of the apparatus, provision is made for rotatingthe grate, and as herein shown, the driving shaft 46 upon which thedriving gear 45 is mounted, has affixed to its outer end a ratchet wheel18 with which a pawl 12 cooperates to advance the ratchet wheel andconsequently to effect rotation of the conical grate when the pawl isadvanced. The pawl is carried on the pawl arm 14, as best shown in Fig.2, which is connected to an arm 16, the latter being connected by a link18 to a crank 88. The crank 80 is arranged to be revolved from anelectric motor 82 through the medium of a reduction gearing 84 of anyusual "or preferred form now upon the market. Provision is made forcontrolling the effective throw of the pawl 12 to control the extent ofgrate movement at each revolution of the crank 80, and as herein shown,a shield member 84 pivoted upon the shaft 46 is arranged to be movedrelative to the pawl so as to slide under a pin projecting from the pawlto maintain the nose of the pawl disengaged from the teeth of theratchet for the desired portion of the normal stroke of the pawl tothereby prevent it from picking up any desired number of teeth. Thepivoted shield is preferably connected to a control link 86 running froma thermostat or from a manual control.

In order to supply fuel to the conical grate to maintain a substantiallyuniform bed of fuel thereon, as herein shown a bulk supply of fuel isstored within a fuel reservoir l4 located above the grate in a positionfrom which the fuel may automatically flow onto the grate by gravity.The flow of the fuel is controlled by'the rate of consumption of thefuel bed in cooperation with the ash discharged therefrom and as long asfuel remains in the hopper a substantially uniform fuel bed ismaintained upon the. grate. During the combustion sufficient air issupplied through the fuel bed to maintain practically the entire lengthof fuel bed incandescent, and the ash resulting from the combustiongradually slides and works downwardly toward the restricted throat orpassage between the skirt 32 and the dead ring 34 preparatory to beingforced over the skirt to drop into the ash-pit where it may convenientlybe caught in a removable ash receptacle not shown.

Referring now more particularly to Figs. 3 to 8,

grate is mounted independently of the remainder of the grates upon theupper end of a, post 15 affixed to the burner pot so to as to permit theupper grate section to rotate about the axis of the post 15. The nextlower of the grate sec- 5 tions 26 is provided with a slot 88 of theshape illustrated and within which a pin 89 depending from the uppergrate section 21 is adapted to travel, so that during the rotarymovement of the main body of the grate about its own axis, the uppergrate section 21 is moved by the engagement of the walls of the slot 88with the pin 89. The post is mounted at one side of the axis of theconical grate, and with this construction, as the conical grate isrotated through the 15 driving mechanism previously described, the uppergrate section is caused to be displaced with relation to the main bodyof the rotating grate in the manner illustrated diagrammatically inFigs. 3, 4, 5 and 6. The result obtained during combustion is that theupper section of the conical fuel bed is agitated by what amounts to arevolution of the conical grate about the post 15, thus expanding andcontracting or kneading the upper portion of the conical fuel bed in amanner such as to reduce to a minimum the tendency of the ash to fusetogether and form clinker at this point.

While the preferred embodiment of the invention has been hereinillustrated and described, it 0 will be understood that the inventionmay be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed is: 1. In acombustion apparatus of the character described, in combination, acombustion chamber, a conical grate mounted within the chamber with theapex thereof uppermost in a position to be rotated about the mainvertical axis, means for 40 slowly rotating the grate, means forautomatically supplying fuel to the upper portion of the grate includinga fuel discharge tube terminating in close proximity to the grate, saidgrate being provided with a top section movably mounted with relation tothe remainder of the grate upon an axis which is non-coincident with theaxis of the grate and connections between said top section and theremainder of the grate whereby during rotation of the main body of thegrate about its axis the upper section of the grate is moved in aneccentric path with relation to the axis of the grate to thereby reduceto a minimum the formation of clinker, in the upper portion of theconical fuel bed supported on the grate.

2. In combustion apparatus of the character described, in combination, acombustion chamber,

aconical grate mounted within the chamber with the apex thereofuppermost in a position to be rotated about the main vertical axis,means for slowly rotating the grate, means for automaticallysupplyingfuel to the upper portion of the grate, said grate being provided with atop section movably mounted with relation to the remainder of the grateupon an axis which is noncoincident with the axis of the grate andconnections between said top section and the remainder of the gratewhereby during rotation of the main body of the grate about its axis theupper section of the grate is moved in an eccentric path with relationto the axis of the grate to thereby reduce to a minimum the formation ofclinker in the upper portion of the conical fuel bed supported on thegrate.

LAWRENCE W. CORBETT.

